Rotary switch



D. P. MOSSMAN ROTARY SWITCH Jan. 6, 194s.

Fild Oct. 7, 1944 3 Sheets-Sheet 1 Jah. 6, 1948. l 4D. P. Mo'ssMAN ROTARY SWITCH v Filed Oct. 7, 1944 v 5 sheets-sheet 2 I I hf/enfer.' A PMoJq-rvnczm Jan. 6, 1948. y D. P. MOSSMAN 2,433,920

ROTARY SWITCH Filed oct. 7, 1944 3 sheets-sheet :5

ad 10o' 56 7,41

EonczvZ/dfmsnmn Patented Jan. 6, 1948 ROTARY SWITCH Donald P. Mossman, Chicago, Ill., assigner to Donald P. Mossman, Inc., Chicago, Ill., a corporation of Illinois Application October 7, 1944, Serial No. 557,595

7 Claims.

The present invention relates to rotary switches and is particularly directed to a rotary switch which can be utilized to actuate a multiplicity of piles of spring contacts in succession. The switch iinds particular utility in those situations where a dozen or more circuits must be checked repeatedly to see if they are in working order. It is a diiiicult matter to mount a row of switches by which you could individually check such circuits in a small space. Also, the individual mechanisms required for the several switches make them expensive.

It is the principal purpose of my invention to provide a rotary switch with a single operating shaft so arranged as to coordinate the snap action of a spring pressed roller on a notched driving member with the spring action of the contacts so that the springs help rather than oppose each other.

My invention contemplates the provision of a rotary switch wherein a single shaft and operating mechanism can be utilized as the means of controlling a relatively large variety of circuits without the necessity of changing anything more than the number of individual banks of contacts to correspond to the circuits to be controlled. The contemplated switch is of such construction as to adapt itself readily to a Wide variation of sizes and numbers of circuits controlled, thus making it possible to standardize most of the parts and yet selectively ll the requirements of the users on a cost basis comparable to mass production even though the requirements of the user are only for a small number of switches.

Other detailed objects and advantages of the present invention will appear more fully as the description proceeds, reference being had to the accompanying drawings wherein a preferred form of the invention is shown. It is to be understood however that the drawings and description are illustrative only and are not to be taken as limiting the invention except insofar as it is limited by the claims.

In the drawings:

Fig. 1 is a view in side elevation of a rotary switch embodying my invention;

Fig. 2 is an end view of the switch shown in Fig. 1;

Fig. 3 is a sectional view taken on the line 3-3 Fig. 5 is a sectional view taken on the line 5-5 of Fig. 3;

Fig. 6 is a fragmentary sectional view taken on the line 6--6 of Fig. 4;

Fig. 7 is a fragmentary sectional View similar to Fig. 3 showing a modified cam construction;

Fig. 8 is a longitudinal sectional view through another form of the invention;

Fig. 9 is a fragmentary sectional view through the modied device on line 9-9 of Fig. 10; and

Fig. 10 is a sectional view taken on the line IIJ-I 0 of Fig. 8 with certain parts broken away.

Referring now in detail to the drawings, the rotary switch is made up primarily of a few simple parts. The body parts are preferably die castings or molded plastics which are readily assembled with springs, levers and plates by screws and posts that are accessible for the assembler. The basic part of the switch construction comprises a switch frame I0. This switch frame comprises a barrel portion II which has one end closed except for a central aperture I2 to receive an operating shaft. The end closure I3 in which the aperture I2 is provided is cored out as indicated at I4 to reduce the amount of metal necessary to make it. At the opposite end of the barrel from the closure I3 an annular flange I5 is provided and on this flange there are a series of six mounting lugs I6. The several mounting lugs have web portions I'I extending to the barrel II so as to give them suiiicient strength. The mounting lugs are screw threaded to receive certain mounting studs and bearing plate studs vthat will be more fully described hereinafter.

A contact support I8 is adapted to be mounted on the end closure I3 of the barrel Il. This contact support is substantially cup shaped with the bottom of the cup cut out as indicated at I9. Around the outer periphery of the contact support I provide a multiplicity of hat faces 20 on which several piles 22 of spring contacts can be mounted. The piles of spring contacts are shown as consisting of sheets 23 of insulation alternating with strips 24 of suitable spring material such as phosphor bronze. The entire spring contact assembly is held together by screws 25 that thread into the flat faces 2D on the contact support I8. It will be noted from an inspection of Fig. 2 that the contact support which is also a die casting has inwardly curved sections 2| between the flat faces 2li so that there is a gap between adjacent faces 20. lThis constructionyis also quite strong. *Contact springs 24 are provided with suitable contacts 26, 21 and wherea plurality of the contact springs are mounted suit;- able spacers such as 28 (see Fig. 1) may be used in accordance with well known practice.

The contact springs are adapted to be operated by means of a cam 29 that is mounted on a cam pinion 3] which in turn is carried by a cam support 3i. The cam support 3| preferably is a metal casting. It is keyed to an operating shaft 32 which is journaled in the bearing l2. The cam pinion 39 is adapted to .engagearing gear 33 so as to rotate the cam 29 as the pinion is-:carried around by the support 3|. The ring gear is fastened to the lugs I6.

A bearing plate 34 carrying a bushing 35 is mounted to the lugs I6 by studs 36. There ,are three of the studs 36 and as shown they.extend through apertures 31 provided.inatheiiingsgear and through spacing bosses 38 on the ring gear into the lugs I6 which are screw threaded to receive the screw threaded ends .of the studs. The studs have hexagonal portions 39 which. areprovided with screw threaded holes 49 to receive headed screws 4 I. The screws 4| clamp the bear- 'ing plate 34 in place. -The bushing 35 and the bearing opening I2 serve to support the shaft 32'for rotation inthe barrel The bushing 35 is staked on the plate' 34.

Referring now tothe cam support 3|, it will be noted that a.key142'securesthis support to the shaft 32. YThe support 3| has a'peripheraL radially extendingflange l43which is provided with a series of apertures "44, any'onefof which-may receive ,the'hase l45 of a stub shaft l46 on which the cam pinion 30 is mounted. "The cam 429 is fixed on the pinion-3D bystaking it on aV polygonal projection 41 of the pinion.

The camsupport 3| lalso has af series of teeth 4.8 .formed thereon .in acircle about-the'axis of the support. These teeth are adapted-tocooperate with'a roller l49 on a detent lever 50 whichv is Apivoted at .5|.to'` the bearing plate 34. The detent lever is .yieldingly urged'toward'the'teeth 48 on the cam support .by a spring' 52, one end of which is secured to `the `lever 'and the other end of which is secured to a-pin y53 that is provided on the bearing plate 34.

.The cam support 3| .has a stop shoulder 54 formed thereon, the stop shoulder being on a smaller radius than the teeth 48, and being axially offset toward the lbearing plate 34 from the teeth 48. This stop shoulder is adapted to engage a pin55 which is mounted on the bearing plate 34.

The frame l is shown by Fig. v2 to have six of the lugs |6. Three of these lugs have been described Yas -receiving the bearing plate studs 36 so as to connect theframe land the bearing vplate together and Iprovide the spaced Ybearings |2 and 35 for the shaft 3-2. The other three lugs |6:are screw'threaded to-receive three mounting studs 56 which in turn have Vscrew threaded-holes therein so that they-may be utilized to mount the switch upon a panel 51 byjmeans of'screws 58 '(see Fig. l). The-six studs 36-56 are-all used in Vsecuring the ring gear 33fto the'frame I0.

Referring'nowfparticularly to Figs. 3 and rv1, the operation of the cam-29 willbe described.

Ity will be -notedthat 'this "cam, `as shown in Fig. 3, `has three projections-Elche of which is shown as engaging the contact'spring 24and lifting it toits maximum position. The'projections -59 fhave theircam'surfaces circular with the `center of thesurface'at the same distance iromfthe'axis of the cam asthe teeth-on thepinion 3|lextend -from the-axis of thepinion. Now as Ythe Vcam moves-intoposition to engagea contactspring 24 it brings a side face ofthe projection-59 against the spring V24and'then as the/pinion and 'cam fare exposed -where vthey caribe-reached readily piles 222.

advance the projection merely rolls on the contact spring surface as it lifts the contact spring thus practically avoiding any appreciable side thrust on the contact spring. Also, the peculiar shape of the projection 59 makes it raise and drop the spring contact in a very short angular move- `ment of thecam about the shaft v32 so that a --quick make and break can be had between the contacts 26 and 21 on the contact springs.

The cams 29 are made with the desired number of projections 59 to t the needs of the contact For example, if the contact piles are spaced ,90 rapart one may use a single pointed cam J49 as -shownzin Fig. 7, In some instances A-upon the-camsuppOrtSI. -It is-obvious that if Athe diameter of the rotary switch is expanded the angular 'displacement between the spring contact piles can be reduced and thus more and more spring-contact piles can be put in a single unit. lIt will beinoted also that theshaft `32 is so positioned withrespect tothe switch assembly that if desired it-can be Lextended and additional -switch'assembliescan be mounted in tandem utilizing the samefshaft 'cooperate contacts of more than one switch assembly. The shaft`32vhas not been shown with any particular operating means connected to'it. Theoperating means may be manual; in which case itwouldbe provided with a handle, ora suitable motor'mayV be connected -to the-shaft'for turning it.

'The-rotary switchhereinbefore described, in

addition to having'lthe advantage of being quite flexible as to the number of circuits'it may control,'has the advantage that the contact springs forv wiring. "In addition the parts of the switch, that is, the'barreldlycup'l, ring gear 3B, cam

:supportSI .andlbearingplate 34, are so con- -structedthat thezsame parts 'are utilized for a llarge .variety of spring Contact assemblies and different cams 29. The bearing plate 34 is shown ras provided with a multiplicity of apertures 60 to receive the rstop pinsA 55 so'that the stop pins can `be put indiierent positions to match the assembly of spring contacts 4on'the cup I3. Likewise the pinion F30 can befmounted in any one of the Aopenings 44 andzmore than one pinion can be used Vwhen desired. This makes the switch quite exible-as'toultimate design without any appreciable lvariation in lthe -basicf construction of the .parts ||,|8,3|,f33 and'34.

Figs. i8, 9 and l0 illustratea somewhat modied form of construction. The construction how- `,ever functions just-the lsame :as that shown in Vthe main form oftheinvention. yIn the modified .construction a-contact imountingcup .6| is provided. This cup has a multiplicity of flat exterior faces such as 52 and 63 uponwhich banks of contact 4springs ycan be mounted. These banks of contact springs are essentially the same as the banks 22 shown in connection with themainform ofthe invention. As shown in Fig. 9 of the drawings a bank comprises alternate insulating strips -64 and contact elements 65and 66. The stationary contact elements are indicated by the numeral 65 and the movableones by the .numeral 66. The springs 65 and 66 and the strips164 are v'apertured to receiveinsulating sleeves-'61andsecuring screws 68. A spacer 69 ls mountedlon the upper contact spring 66 so that when the lower contact spring 66 is actuated the motion will be transmitted to the upper contact spring.

In order to actuate the movable contacts I utilize a cam 18 which is similar in all respects to the cam 29. This cam is staked on a reduced end portion 1| of a pinion hub 12. The pinion hub is xed on a shaft 13 which is rotatably carried by a cam support 14. The hub 12 has a pinion portion 15 thereon meshing with a ring gear 16.

There may be as many of the cams 18 and pinions 15 in this form of the invention as may be desired. For example, in Fig. 10 of the drawings provision has been made for four of the cams and pinions.

The cam pinion and ring gear assembly are connected with the contact bank carrying cup by means of the construction shown best in Fig. 8 of the drawings. A series of flat pieces of insulating material, indicated at 11, are .formed with a central opening 18 and six radially projecting portions 19. These pieces 11 have apertures around the central opening 18 by which they are riveted between two metal washers 80 and 8 I'. Four rivets 82 are used to clamp the pieces 11 between the washers 80 and 8|. 'I'he rivets 82 are hollow and interiorly threaded so that the cup member 6| can be fastened to these rivets by suitable screws 83.

The washer 8| has a central aperture 84 which serves as a bearing for one end of a shaft 85. The shaft 85 carries the cam support 14, there being a hub 86 keyed to the shaft by a key 81 on which the cam support 14 is secured. The hub 86 may be made of a die casting or suitable material of that type. The cam support 14 is simply a ring of any suitable material to which the cams and pinions can be mounted. Any suitable method of mounting the cam support on the hub 99 may be used. For example, I provide a shoulder 88 on the hub and stake the cam support onto the shoulder.

The ring gear 16 is secured to the radially projecting portions 19 of the pieces 11 by long screws 89 and 90 that extend through the portions 19 then through suitable spacers 9| and through the ring gear 16. The screws 89 are somewhat shorter than the screws 90 and they receive nuts 92 so as to clamp the ring gear against the spacers 9|. There are three of the screws 89 spaced 120 apart. There are also three of the screws 90 alternating with the screws 89. The three screws 90 serve to secure the mechanism to a combination mounting and bearing plate 93. Suitable spacers 94 are provided between the ring gear 16 and the plate 93 and one of these spacers provides a bearing for a lever arm 95, the lever arm 95 being made up of two spaced bars 96 and 91. These bars carry a roller 98 between them, the roller being situated between the ends of the bars. The roller 98 is adapted to engage a notched member 99 that is also xed on the hub 86.

The notched member comprises a star wheel which is staked on a shoulder |09 provided on the hub 86. This star wheel and the roller 98 are preferably made of hardened steel capable of withstanding hard wear. The roller 98 is pressed against the teeth |0| of the star wheel 99 by a spring 02, one end of which is hooked over a pin 03 which connects one end of the bars 96 and 91. The other end of the spring is secured on a pin |04 that is provided on the mounting plate 93. The star wheel 99 has a lug |95 struck up therefrom toward the mounting plate 93 and the mounting plate 93 has a stop pin |06 thereon so as to limit the rotation of the star wheel in either direction. The stop pin |06 can be mounted in any one of a plurality of positions since the mounting plate 93 is provided with an annular series of openings |`01 in which the stop pin can be placed. The mounting plate 93 also serves as a support for a bearing |08 for the shaft 85. The bearing is staked in the mounting plate in a well known manner.

It is believed that the details of the modified construction shown in Figs. 8 to 10, inclusive, will be clear from the foregoing description. This form of the invention and the main form of the invention operate in essentially the same manner. One particular feature of importance in the operation of these devices is the arrangement whereby the cams 29 and 10 are caused to actuate the movable contact springs. In a heavy bank of contact springs the resistance of the springs is quite substantial and this normally places quite a heavy load on the shaft 32 or 85 as the case may be. The present design is such that the spring which presses the detent lever against the star wheel in both forms of the invention is utilized to counteract or offset the resistance of the contact springs. trated by comparing the positions of the roller 98 and the cam 10 in Fig. 10 of the drawings.

The cam 10 has one of its projections 10' in engagement with the contact spring 66 and lifting the spring. Note that the roller 98 is moving down the inclined surface |0|a of the projection |0| with which it is engaged. This movement is being aided by the spring |02 which is a substantial spring so that there is a force tending to rotate the star wheel 99 in the right direction to complete the lifting of the spring 66. The parts are so arranged that when the roller 98 is climbing out on the face of the projection |0| against the force of the spring |62 a projection 19' is being moved inward in the direction of the force of the contact spring 66, so that in all positions the spring 66 and the spring |62 act to offset each other and reduce the power` necessary to rotate the shaft 85.

The construction is also advantageous in another respect. When the cam support 86 is moving in a clockwise direction with the star wheel 99 the cam itself is moving in a counterclockwise direction. The result is that a linkage is accomplished between the axis of the shaft 85, the axis of the cam 10 and the point of engagement between the spring 66 and the projection 16 whereby a greater lever advantage is obtained against the spring 66 as the spring is moved farther out. This arrangement also tends to reduce the load on the shaft 85. c

We have described the particular functioning of the cams with a star wheel and the spring in connection with Fig. 10. The same relation exists in the mechanism shown in Figs. 1 to '7, inclusive. However, it is believed that the single showing in Fig. 10 and the foregoing description are adequate to illustrate this important feature of the invention.

From the foregoing description it is believed that the nature and advantages of the present invention will be readily apparent to those skilled in this art.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A switch of theI character described, comprising a spring contact bank carrying frame having circumferentially arranged mountings for the This is best illus-V banks of contacts, means formounting a shaft for rotation about the axis on which the banks -of contacts are arranged, said means com-prising spaced bearings fixed to said frame, a ring gear f'xed to said fra-me, a cam support keyed to said shaft, a pinion on said ycam support engaging rsaid ring gear, a cam fixed -to said pinion `having jits surface formed to engage and -lift -the movable contact springs of said banks of contact, anotched 'member fixed on said shaft, and aspring pressed lever having a roller riding .on the notches of said member, Vthe contact spring lifting surface von the ,cam and the notches on said notched member being so mounted with relation to .each other .that the spring pressure on .the lever and the ,spring pressure of the spring contact .offset eachother. 2. A switch ofthe character described, comprising a spring contact bank carrying frame having circumferentially arranged mountings for 4the lbanks of contacts, means for mounting va shaft for rotation about the axis on which ,the banks-of vcontacts are arranged, said means lcomprising spaced bearings fixed to said frame, .a ring gear .ixedto said frame, a cam support Akeyed to s aid shaft, a pinion on said cam support engaging said ring'gcar, a cam fixed to said pinion 'having Va projection operable to engage the movable contact springs of said banks ofcontacts, la notched lmember fixed onsaid shaft, and a spring pressed ,lever having a roller riding lon the notches of said member, the contact spring lifting `projection on the cam and the notches on said notched meinber being so mounted with relation to .each other ythat the spring pressure on the lever and the spring pressure of the spring contact offset each other, the contact bank mounting portion of the frame comprising a cup shaped member sep- Varably mounted to the frame.

.of banks of contacts, a cam support on said shaft,

a cam pivoted on the support means operable by rotation of the shaft to turn the cam on its pivot in the opposite direction to the rotation of the shaft, said cam having a cam surface operable to move certain of the spring contacts of a bank radially as the shaft is rotated to move the cam past the bank, and means cooperating with the shaft to oppose the force of said spring contacts on the cam, said means comprising a spring pressed detent and a notched member over which the detent is passed by rotation of the shaft, the low points of the notched member being in engagement with the detent when the Vcam is .positioned to give the spring contacts of the bank it is actuating the greatest deflection.

4. A switch of the character described, comprising a spring contact bank carrying frame having circumferentially arranged mountings for the banks of contacts, means formountinga shaft for rotation about the axis on which the banks of contacts are arranged, said means comprising spaced bearings fixed to said frame, a ring gear fixed to said frame, a cam support Akeyed to said shaft, a pinion on said cam support engaging lSaid ring gear, a cam fixed to said pinionhaving its surface formed to engage and lift `the movable -GQIltac-t Vsprings of said banks of contacts, `and means cooperating with VVthe shaft to oppose the force of said spring contacts on the cam, said means lcomprising a spring ,pressed .detent `and a notched member over which 4the detent is passed greatest deflection.

5. In a switch of the character described, a

.springcontact bank carrying cup annular in cross Ysection with circumferentially spaced mounting seats for banks of spring contacts, a shaft sup.- porting member xed to one end of said .cup and operable to vcenter a shaft with 1respect yto the vcontact bank seats, a shaft extending away from the cup, banks of spring contacts on said seats projecting vfrom the cup in the same direction as the shaft, and means secured to the cup by said Yshaft supporting member and extending `beyond lsaid member for mounting a rsecond shaft supporting vmember in spaced relation to said first named member.

6. In a switch of the character described, a spring contact bank carryingcup annular in cross section with circumferentially spaced Amounting seats .for banks of rspring contacts, ,a shaft supporting member xed to one end of said c up and operable to center a shaft with respect tothe contact `bank seats, a shaft extending away from the cup, banks `of yspring contacts on said seats projecting from the cup in the same direction as the shaft, means secured to cup by said shaft supporting member vand extending Ybeyond said member for lmounting a second shaft supporting member in spaced relation to said first named member, vand contact actuating means mounted on the shaft betweensaid shaft supportingmembers.

7. In a lswitch of the character described, ,a spring contact bank carrying cup annular in cross section with circumferentially.spaced mounting seats for banks of spring contacts, ,a shaft supporting member fixed to one .end of said cup and operable to center a shaft with respect 'to the `contact bank seats, a shaft, andmeans secured to the c up by said shaft supporting member and extending beyond said member formounting a second shaft supporting member in spaced relation to said iirst named member, said means compris- Ving a ring with radial arms thereon, a ring gear,

anda combined bearing and Vmounting plate all in spaced relation to each otheraxiallyof -said shaft, and means connectingthem together in the spaced relation. l

DONALD P. MOSSMAN.

REFERENCES .CITED The following references areof record inthe leof this patent:

:UNITED STATES yPAIENTS 

